|Cả nhà dưới chân tháp Big Beng!|
All in all, it's because you are the one who cares about everyone around you. They can lean on this occasion to show you their appreciation. It would feel more natural, wouldn't it? Just like me, I don't normally text to you not because of I don't care but it is not the way I am used to showing my thoughts. So your birthday is an excuse to express them naturally.
I know I still have one more year to go. Hard it is for me but it is not easy for you either. I am always ready as I've learnt from you the dignity that no university can offer me to deal with real life.
Thank you daddy. Even if one year of your life has passed, you don't lose anything but gaining by helping a lot of people around you.